Location coordinates of rodents and ectoparasites collection sites in Thailand (2012–2013).

<p>Surveillance activities were conducted in 4 regions and 8 provinces in Thailand. The Northern region (Chiangrai and Phayao provinces), the Northeastern region (Loei and Nong Bua Lam Phu provinces), and the Southern region (Chumphon and Surat Thani provinces).</p><p>Location coordinates of rodents and ectoparasites collection sites in Thailand (2012–2013).</p

Percent similarity of <i>glt</i>A sequence for <i>Bartonella</i> identification detected from rodents (R) and their associated ectoparasites; Mite (M), flea (F), tick (T), and louse (L).

<p>^a Group 1 consists of sample no. R1023, R1025, R1026, R1028, R1181, R1195, R1197, L1028, M1200, L1206, L1354, and L1355.</p><p>^b Group 2 consists of sample no. R1012, R1033, F1413, F1437, F2386, F2495, and F2532.</p><p>^c Group 3 consists of sample no. T1005, L1025, M1189, L1194, L1227, and L1596.</p><p>^d Group 4 consists of sample no. R1072, R1073, R1136, R1144, R1168, L1080, T1513, and T1521.</p><p>Percent similarity of <i>glt</i>A sequence for <i>Bartonella</i> identification detected from rodents (R) and their associated ectoparasites; Mite (M), flea (F), tick (T), and louse (L).</p

Phylogenetic relationship between <i>glt</i>A sequences of <i>Bartonella</i> species.

<p><i>Bartonella</i> species detected from rodents and their associated ectoparasites; mite (M), flea (F),tick (T), and louse (L), along with reference sequences (GenBank accession numbers are noted after each sequence). Only bootstrap replicates of >50% are shown. The <i>Bartonella</i> species detected in this study are indicated in bold letters.</p

The Distribution and Diversity of <i>Bartonella</i> Species in Rodents and Their Ectoparasites across Thailand

<div><p>Our study highlights the surveillance of <i>Bartonella</i> species among rodents and their associated ectoparasites (ticks, fleas, lice, and mites) in several regions across Thailand. A total of 619 rodents and 554 pooled ectoparasites (287 mite pools, 62 flea pools, 35 louse pools, and 170 tick pools) were collected from 8 provinces within 4 regions of Thailand. <i>Bandicota indica</i> (279), <i>Rattus rattus</i> (163), and <i>R</i>. <i>exulans</i> (96) were the most prevalent species of rats collected in this study. Real-time PCR assay targeting <i>Bartonella</i>-specific <i>ssr</i>A gene was used for screening and each positive sample was confirmed by PCR using <i>nuo</i>G gene. The prevalence of <i>Bartonella</i> DNA in rodent (around 17%) was recorded in all regions. The highest prevalence of <i>Bartonella</i> species was found in <i>B</i>. <i>savilei</i> and <i>R</i>. <i>rattus</i> with the rate of 35.7% (5/14) and 32.5% (53/163), respectively. High prevalence of <i>Bartonella</i>-positive rodent was also found in <i>B</i>. <i>indica</i> (15.1%, 42/279), and <i>R</i>. <i>norvegicus</i> (12.5%, 5/40). In contrast, the prevalence of <i>Bartonella</i> species in ectoparasites collected from the rats varied significantly according to types of ectoparasites. A high prevalence of <i>Bartonella</i> DNA was found in louse pools (<i>Polyplax</i> spp. and <i>Hoplopleura</i> spp., 57.1%) and flea pools (<i>Xenopsylla cheopis</i>, 25.8%), while a low prevalence was found in pools of mites (<i>Leptotrombidium</i> spp. and <i>Ascoschoengastia</i> spp., 1.7%) and ticks (<i>Haemaphysalis</i> spp., 3.5%). Prevalence of <i>Bartonella</i> DNA in ectoparasites collected from <i>Bartonella</i>-positive rodents (19.4%) was significantly higher comparing to ectoparasites from <i>Bartonella</i>-negative rodents (8.7%). The phylogenetic analysis of 41 <i>glt</i>A sequences of 16 <i>Bartonella</i> isolates from rodent blood and 25 <i>Bartonella</i>-positive ectoparasites revealed a wide range of diversity among <i>Bartonella</i> species with a majority of sequences (61.0%) belonging to <i>Bartonella elizabethae</i> complex (11 rodents, 1 mite pool, and 5 louse pools), while the remaining sequences were identical to <i>B</i>. <i>phoceensis</i> (17.1%, 1 mite pool, 5 louse pools, and 1 tick pool), <i>B</i>. <i>coopersplainensis</i> (19.5%, 5 rodents, 1 louse pool, and 2 tick pools), and one previously unidentified <i>Bartonella</i> species (2.4%, 1 louse pool).</p></div

Comparison <i>of Bartonella</i> prevalence in ectoparasites collected from <i>Bartonella</i>-positive and <i>Bartonella</i>-negative rodents.

<p>^a There are 2 samples where <i>Bartonella</i> was detected in host (<i>R</i>. <i>rattus</i>), mite, and lice; 1–4 pools of ticks and fleas can be collected from one rodent.</p><p>^b<i>Bartonella</i> DNA prevalence in ectoparasites collected from positive rats (19.4%) were higher significantly (Chi-Square Tests, <i>P</i> = 0.003) comparing to ectoparasites from negative rats (8.7%).</p><p>Comparison <i>of Bartonella</i> prevalence in ectoparasites collected from <i>Bartonella</i>-positive and <i>Bartonella</i>-negative rodents.</p

Prevalence of <i>Bartonella</i> DNA among wild-caught rodents and their associated ectoparasites collected from different regions and provinces in Thailand, 2012–2013.

<p>^a<i>Bartonella</i> DNA was detected by <i>ssr</i>A and <i>nuo</i>G genes. The positivity for each sample was recorded only when 2 assays produced the concordant results.</p><p>^# Two <i>B</i>. <i>indica</i> rats had 2 positive tick pools.</p><p>^£ One <i>R</i>. <i>exulans</i> had 2 positive flea pools.</p><p>Prevalence of <i>Bartonella</i> DNA among wild-caught rodents and their associated ectoparasites collected from different regions and provinces in Thailand, 2012–2013.</p

<i>Bartonella</i> species identified in rodents and their associated ectoparasites based on <i>glt</i>A gene sequence similarities

<p>^a<i>L</i>. <i>deliense</i>.</p><p>^b Mite species was not available since there were only 3 mites collected from this host and no slide was made for species identification.</p><p>^<b>c</b><i>Bartonella</i> DNA was equally detected in <i>Polyplax</i> and <i>Hoplopleura</i> lice.</p><p>^d<i>Polyplax</i> spp.</p><p><i>Bartonella</i> species identified in rodents and their associated ectoparasites based on <i>glt</i>A gene sequence similarities</p

Distribution of <i>Bartonella</i> DNA among rodent species in different regions and provinces of Thailand, 2012–2013.

<p>^a<i>Bartonella</i> DNA was detected by <i>ssr</i>A and <i>nuo</i>G genes. The positivity for each sample was recorded only when 2 assays produced the concordant results.</p><p>Distribution of <i>Bartonella</i> DNA among rodent species in different regions and provinces of Thailand, 2012–2013.</p

Bartonella species and trombiculid mites of rats from the mekong delta of Vietnam

International audienceA survey of Bartonella spp. from 275 rats purchased in food markets (n=150) and trapped in different ecosystems (rice field, forest, and animal farms) (n=125) was carried out during October, 2012-March, 2013, in the Mekong Delta of Vietnam. The overall Bartonella spp. prevalence detected by culture and PCR in blood was 14.9% (10.7-19.1%), the highest corresponding to Rattus tanezumi (49.2%), followed by Rattus norvegicus (20.7%). Trapped rats were also investigated for the presence and type of chiggers (larvae of trombiculid mites), and Bartonella spp. were investigated on chigger pools collected from each rat by RT-PCR. A total of five Bartonella spp. were identified in rats, three of which (B. elizabethae, B. rattimassiliensis, and B. tribocorum) are known zoonotic pathogens. Among trapped rats, factors independently associated with increased prevalence of Bartonella spp. included: (1) Rat species (R. tanezumi); (2) the number of Trombiculini-Blankaartia and Schoengastiini-Ascoschoengastia mites found on rats; and (3) the habitat of the rat (i.e., forest/fields vs. animal farms). The prevalence of Bartonella infection among chiggers from Bartonella spp.-positive R. tanezumi rats was 5/25 (25%), compared with 1/27 (3.7%) among Bartonella spp.-negative R. tanezumi rats (relative risk [RR]=5.4, 95% confidence interval [CI] 0.68-43.09). The finding of Bartonella spp.-positive chiggers on Bartonella spp.-negative rats is strongly suggestive of a transovarial transmission cycle. Rats are ubiquitous in areas of human activity and farms in the Mekong Delta; in addition, trapping and trading of rats for food is common. To correctly assess the human risks due to rat trapping, marketing, and carcass dressing, further studies are needed to establish the routes of transmission and cycle of infection. The widespread presence of these zoonotic pathogens in rats and the abundance of human-rat interactions suggest that surveillance efforts should be enhanced to detect any human cases of Bartonella infection that may arise